The sorption/desorption behavior of phenanthrene in five aquatic sediments from Chinese southern rivers and lakes were studied using multiple cycles of sorption/desorption experiments. The results showed that the sorption of phenanthrene on sediments was proportional to the content of organic carbon and that there were irreversible sorption processes. When the total sorption was separated into reversible and irreversible fractions, reversible sorption of phenanthrene on sediments could be better predicted b...